The central purpose of the proposed study is to provide evidence of the distribution of alcohol, drug and/or mental disorders (ADMs) and dual disorders among homeless adults, and to explore how these disorders are related to entitlement status, in particular with regard to need and service utilization. The distribution of ADM disorders and the relationships between ADM disorders and dual disorders to entitlement status, as well as the need for and use of services will be analyzed in two representative samples of homeless women and men surveyed in 1985 and 1987. The study will use data from a 1987 epidemiological survey of NYC homeless adults to replicate and extend an analytic model developed on a 1985 epidemiological survey. Correlates and predictors of Medicaid previously analyzed will be extended to include a full range of other entitlements: SSI, Veteran's Benefits, Medicare, Unemployment Insurance, Public Assistance, AFDC, Social Security, and Social Security Pension. Use of and need for services, especially alcohol, drug and mental health services, will be analyzed in relationship to entitlement status using two classifications of drug, drinking and mental problems/disorders derived from other analyses of the 1987 survey. Homeless adults with co-occurring disorders will be specifically targeted for study. The explanatory value of barriers to obtaining entitlement coverage, including policy implications, will be studied. Such barriers include real and perceived obstacles as well as dissemination and level of correct entitlement information. The utility of the proposed research is fourfold: 1) to determine the distribution of ADM and dual disorders in the 1985 and 1987 epidemiological survey populations and to further demonstrate the validity of the classification systems; 2) to identify the prevalence of ADMs, including co-occurrences, in groups with differing entitlement status; 3) to develop an informed basis for subsequently carrying out prospective studies of the relationship between entitlement status and ADMs among the homeless, and; 4) to yield new insights relevant to the development of appropriate policy regarding entitlements for homeless adults, particularly for those with ADM and dual disorders.